A resurgence of the virus would strain local health systems already close to a breaking point—but they might be more prepared the second time around.

That’s what disease experts are saying about a second wave of coronavirus cases, even as governments and health systems across this country are overwhelmed by a still-rising first wave of patients requiring hospital care. But the likelihood is getting more attention across the world, as other countries that are further along in their disease progression start to see the end of their initial wave of Covid-19 cases and, along with low numbers, begin loosening restrictions on movement and gatherings.

If Covid-19 follows the pattern of nearly every other studied pandemic, it’s likely that even if we “flatten the curve”—the term for reducing the spread of the respiratory illness to a level manageable for most health systems—we still won’t be done with the disease when that curve starts to fall. Many epidemiologists now point to the 1918 Spanish flu as a predictor of what might happen next. It came in three waves, starting in the spring and resurging in the fall and winter, with the second wave killing the most people. The cities in the U.S. that were hardest hit by that second wave were those that eased up on social distancing measures first.

“In our past research on pandemic flu we have seen multiple waves,” said Pinar Keskinocak, president of the Institute for Operations Research and the Management Sciences and a professor at Georgia Institute of Technology. “Right now, we’re talking about flattening the curve, and that’s great, but there’s a chance we may see more than one curve. We’re still in the increasing part of what might be only the first curve.”

President Trump is presenting a rosier scenario, predicting that the U.S. can try to reopen businesses and relax restrictions by Easter. That message is contradicted not only by governors and other political leaders who are regularly extending state and local restrictions, but also by members of the White House coronavirus task force. Dr. Anthony Fauci, the NIH infectious disease expert, on Wednesday warned that “we really need to be prepared for another cycle.”

Covid-19 could resurge in four major ways, said Julie Swann, a professor at North Carolina State University who advised the Centers for Disease Control and Prevention on its H1N1 pandemic response in 2009. In the first scenario, officials relax social distancing and shutdown measures and, after a few weeks, the highly contagious disease flares up again relatively quickly—just like what happened with the Spanish flu. In the second, the virus could die out in the northern hemisphere with the arrival of summer’s higher temperatures and humidity levels, but then flare back up in the fall. In the third, the virus could mutate and people could lose their immunity and get reinfected. In the fourth scenario, the virus could again surge in months with mass travel for major holidays, like November and December. Because all these possibilities could happen, Swann said we might be looking at multiple waves.

If the virus reemerges, it seems likely that the first cases of a second wave would be in China. It was the first country to report cases in December before putting extreme lockdown measures in place that officials say can safely end by early April. In the disease epicenter of Wuhan, no new domestic cases were reported this week for the first time since December, although there were 34 cases that officials believe were imported via air travel from Europe. “We should be watching China closely to see if they have a resurgence,” Swann said. “But it’s not a one-to-one comparison with the U.S. They have a different level of density and connectedness between communities, and the virus may have been circulating for longer than we realize, giving them a different level of immunity.”

But as calls for second wave preparations gain urgency, most local health systems say they are still fighting to be fully prepared for the first. Dr. Joshua White, the chief medical officer at Gifford Medical Center in the small community of Randolph, Vermont, said his hospital is not as well-resourced as those in metropolitan areas. Small hospitals across the country are struggling with “razor-thin margins,” he said, and will be hard hit by indefinitely postponed elective surgeries and reduced clinic volumes. “We certainly don’t have a massive health force or the financial resources a lot of other places have,” he asid. “We don’t normally run ICU-level care but are fully expecting that we’ll have to.”

If a second wave does come, though, White said hospitals like his will be better equipped to triage, diagnose, and treat patients when seeing the symptoms of Covid-19 a second time. “There will definitely be challenges, but on the whole we’ll be much better prepared to handle it,” he said. “Systems are being set up at a much faster rate than normal. Everybody is working around the clock. If we get a second surge, we’ll know how to handle it.”

Local health departments that are in charge of monitoring disease progression in their communities would also be better prepared to identify a resurgence because they know where to look. Places like nursing homes, which are currently showing themselves to be uniquely vulnerable to the virus in communities across the country, will be closely watched going forward, said Dr. Oscar Alleyne, the chief of programs and services for the National Association of County and City Health Officials. “We’ll have a leg up in terms of monitoring and responding,” he said. “We’ll have better and more frequent testing abilities from private, state, and local labs. We could predict and focus on the areas where it could potentially flare up. We’ll have better working knowledge based on the experience of dealing with the initial outbreak.”

Where a second wave becomes harder to deal with, though, is the drain on resources. While PPE and other necessary devices like ventilators may be better stockpiled for a resurgence, medical personnel will likely be fatigued—especially in communities like Randolph where hospital and public health teams are small and there isn’t a deep bench to pull from. “We need to think about how we can supplement medical personnel who can step into not only a resurgence of this outbreak, but all the other diseases that affect our world on a daily basis. Heart disease, STDs, cancer—those don’t stop in a pandemic,” Alleyne said.

How Are Local Health Systems Preparing for a Second Wave?

Right now, state and local government officials are likely too preoccupied with the first crisis to even think about a second wave of coronavirus cases. A representative from the Vermont Department of Health said that “at this point, we’re still in the shadow of the first wave” and focused on getting through it. In New York City, an epicenter of the virus in the United States, a representative from the Department of Health gave a nearly identical response. In King County, Washington, the area around Seattle, the Public Health Department said that “there’s a lot happening” to “safely make it through the current crisis.”

In many ways, that isn’t surprising, said Dr. Alleyne. Local governments have been developing pandemic preparedness plans for years and already have experience combating infectious diseases—but even working on SARS, MERS, and H1N1 cases hasn’t fully prepared them because of the sustained and rapid spread of Covid-19, the lack of any immunity, and the limited availability of protective equipment. “This is a significant hit on the health system,” Alleyne said. “Health departments need to focus on the now because it’s such a daunting task before them.”

Local governments will eventually have to put contingency plans in place for a possible second wave, but Alleyne said the time for that hasn’t arrived yet. He served as director of epidemiology and public health planning for Rockland County, New York during the H1N1 epidemic, which had a first wave in the spring of 2009 and a second wave in the fall. He found the resurgence was not as bad as the initial outbreak because some people had gained immunity. “There will be a point when we will see health departments pivot and allocate resources for what comes next,” he said. “In the middle of the front-end pike in these cases, though, it’s going to be very difficult.”

H1N1 offers a lot of helpful parallels for resurgence planning because it came in multiple waves—but there are also some key differences between both the viruses and our responses to them, explained Swann. “The reason we see something different is a function of how many people get infected, how many get infected simultaneously, and how long they need critical resources,” Swann said.

H1N1 primarily targeted the very young and the very old, which made it easier to initially get vaccines to the people at highest risk of infection. Covid-19 affects a broader range of people, which would make vaccine targeting more difficult, but Swann said that it could happen once a vaccine is developed. “You could definitely imagine something like a Covid-19 vaccine requirement at nursing homes,” she said. But she said it was unlikely we would arrive at a place where a Covid-19 vaccine is made mandatory for children like the vaccines for more infectious diseases like measles. “This is not as severe a disease as one like Ebola or Smallpox. And keep in mind that the flu kills thousands of people every year in America, and we don’t have a requirement for that vaccine, either.”

A key similarity between H1N1 and Covid-19, though, is the broader questions the diseases raise about the American model of dealing with pandemics: Should we have stronger price gouging laws to prevent predatory behavior during pandemics? Should more Americans have paid sick leave? And perhaps most important to our preparedness for a second wave: Should we be better funding public health?

What Will the Pandemic Cause Us to Reconsider?

Many public health officials are hopeful that Covid-19 could be the wakeup call that America needs to rethink the value of staunch individualism in times of communal crises. Dr. Brian Castrucci, president of the public health focused de Beaumont Foundation, said that in usual times the “underfunding of public health isn’t breaking news,” but that a pandemic—and the threat of a second wave of it—has suddenly put our system’s insufficient resources on everyone’s radar. “This is where H1N1 and Ebola never got too,” he said. “This is a real moment of introspection for the country. We’re very much focused on what’s happening now, about the pebble hitting the water. It’s time to start thinking about the ripples.”

But in Vermont, White said that his biggest concern is that coronavirus will go the way of other major public health concerns: a lot of initial hype and then … nothing. “We get ramped up at the beginning, then we’ll develop a vaccine, then it drifts away, and with our current news cycle, we forget,” he said.

Another outbreak like Covid-19, or SARS, or Ebola is inevitable because the world is too globalized to ever fully eliminate widespread infectious diseases. Countries like Singapore, Japan, and South Korea have shown this month that they were much more prepared than other parts of the world and have effectively flattened the curve for their residents—in part because these same countries have heavily invested in public health in recent years and have universal health care systems. “Americans need to realize that a lot of what is happening in our country right now is because we don’t widely value public health,” White said. “It is not something we’ve demanded our politicians invest in. This is something we think happens somewhere else, and we ignore it until it’s on our doorstep.”